The narco-analysis tests carried out on alleged Naxalite Arun Ferreira, a Bandra resident who was arrested along with three others in Nagpur on May 8, at Kalina Forensic Science Laboratory have failed to yield effective results. This, even as the senior Naxalite cadre contradicted himself occasionally, said the police.

The police alleged that the tests did not throw up "clinching" results as no police officer was allowed in during the interrogation — something that marred the prospects of an "interactive exchange" between the police and the suspect.

According to sources, the police had prepared a pointed set of questions to be hurled at Ferreira during the narco-analysis tests. The question set was designed to make him admit or deny his recent involvement in the overall Naxalite-Maoist scheme of things across central India.

"But although Ferreira was found to glaringly contradict himself on a couple of occasions, there was no immediate reactive response (in terms of artfully framed questions) from the investigating officers (making the suspect speak his mind out) geared to elicit real information out of him," said a senior anti-Naxalite unit officer who spoke to DNA on conditions of anonymity.

"We approached the director of the forensic science laboratory on the matter but the authorities chose to perform brain-mapping and polygraph tests on Ferreira instead," the officer added.

When contacted, Kalina Forensic Science Laboratory director Rukmini Krishnamurthy, however, said, "The tests were carried out scientifically and yielded good results which even satisfied the police. We stuck to all standard protocol during the tests."